In recent years various members of the sesquiterpene family have drawn considerable attention as a result of their potent activity as cytotoxic agents. These include the germacranes, elemanes, eudesmanes, and guaianes. Although the carbon skeletons vary enormously among these derivatives, the required structural unit for in vivo activity appears to be the same, i.e., an alpha-methylene-gamma-lactone grouping with a complementary hydroxyl derivative in the homoallylic position. There are apparently no procedures available which would allow for the facile introduction of both of these groupings into molecules of biological importance, in which the relative stereochemical orientations of the lactone ring and the hydroxyl derivative might conceivably vary in eight possible ways. This proposal demonstrates that it should be possible to approach all of these varied structures through the intermediacy of a single structural entity. The proposed transformations follow the precedence of well established chemistry, and if successful would represent a uniquely efficient route to all of the materials described.